It is often useful to provide a timer switch operative for a selected interval of time after which an electrical switch is activated or deactivated as desired. Such timers of conventional construction usually employ clock or other mechanical or electromechanical mechanisms not usually implementable in a manner to suit many intended installation requirements. For example, it would often be desirable to install a timer switch in a standard switch outlet to convert a switch position in a home, office or other facility to one having a timing rather than merely an on-off capability.